Finger-contact for electric controllers.



No. 329,403. FAIEN'IED 2 .2" 28, jifl F. E. IMBSON. FINGER CONTACT FORELECTRIC CONTROLLERS.

APPLICATION FILED APB-.3. 1906.

WITNESSES: INVENTOR:

FRANCIS ERNEST IMESON, OF T HORNA BY-ON'TEES, ENG LAND.

FINGER-CONTACT FOR ELECTRIC CONTROLLERS- Specification of LettersPatent.

Patented Aug. 28, 1906.

Application filed April 3.1 906. Serial No. 309,609.

T 0 all whom it may concern.-

Be it known that I, FnANcIs ERNEST InnsoN, a subject of the King ofGreat Britain and Ireland, residing at Thornal y-on-Tees, in the countyof York, England, have invented a new and useful Im rovement inFinger-Contacts for Electr c ontrollers, of which the following is aspecification.

This invention relates to an improved controller finger-contact fortransmitting electric current in controllers as used in connection withmotors for electric traction and for crane, hoist, mining, and generalelectrical work.

In controllers of the types hitherto in use the finger-contacts havebeen found to quickly lose their efliciency, mainly by reason of theexcessive friction and o the burning or fusing to which they are liable.

The object of my presentinvention, therefore, is to )rovide a controllerfinger-contact which she] be more durable and efficient in transmittingthe current and which shall not be readily liable to such burning orfusing.

My invention is illustrated in the accompanying drawings, in whichFigure I is a side view of my improved controller finger-contact withterminal roller C, as hereinafter described. Fig. 2 is a plan of same.Fig. 3 is a side view of my improved controller linger-eoutact withterminal roller C and side protecting-tips Ii II, as hereinafterdescribed. Fig. 4 is a detail view of pin I), as hereinafter referredto. Fig. 5 is a detail View of the terminal roller C, as hereinafterdescribed.

Similar letters of reference are employed to indicate correspondingparts throughout the several views.

According to my said invention the finger A is provided with a terminalroller C, of any suitablemctal, mounted upon aloosely-fitting reversiblepin D and adapted to be revolver thereon by contact with thecontact-cylinder of the controller, the said finger A being so designedas to permit of the roller- C being changed without necessitating theremoval of the body of the finger when once fixed in position. The saidpin I) is fixed by means of a small stud G or by any other convenientdevice, and the roller C is made with a slight boss N at each side inorder to reduce the friction with the end lugs of the finger A.

The finger A is also provided with a s ring B to assist in collectingand transmitting the current from or to the roller C, the said collector-spring B being slotted at H for adjustment and being split at Jto insure perfect contact with the roller C and being adjustable as toits pressure upon the roller C by means of a screw K. Thiscollector-spring I3 forms an efficient conductor for the current, andtherefore prevents any possibility of local heating due to badconnection. In certain cases it becomes necessary that the said terminalroller C shall be protected from sparking, and for this purpose Iprovide tips or shields IA L at each side of the roller C, so that inopening and closing the circuit the said tips intercept and considerablyreduce the are from the roller-surface. The said tips IA L may be ofcopper, carbon, or other suitable material and are supported, preferably, upon the ends of the aforesaid spring B and of a second spring M.

E is the adjustment-spring, attached to the body of the finger A byrivets or screws I, and F is the adjustment-screw.

The use of my improved controller fingercontact is found also toconsiderably lengthen the life of the contact-cylinder of the controllerby reason of the enormous reduction of friction.

I claim 1. The combination, with a contact-finger provided with anadjusting-screw at one end and having a roller j ournaled at its otherend, of a collecting-spring provided with an adj usting-slot at one endfor engaging with the said screw and having its other end arranged tobear on the said roller, and a pressure-adjusting screw engaging withthe middle parts of the said spring and finger.

2. The combination, with a contact-finger, of a roller j ournaled at oneend portion of the said finger, a collecting-spring having one endortion secured to the said finger with its middle portion bearing on thesaid roller, and a protecting-tip secured to the free end portion of thesaid spring adjacent to the said roller.

3. In an electric controller, the finger-eontact having terminal rolleror runner C, collecting-spring B, and rotecting ti sorshields L L,substan tiall as ierein described, for the purpose s ccifie RANCISERNEST IMESON.

Witnesses:

JOHN E. VVALsn, ALLAN BENNETT.

